FIGURE 2.

TRAMP does not enhance RNA degradation by the core exosome. A, silver-stained polyacrylamide gel of 2.5 μg of core exosome purified from an RRP46-TAP strain. The positions of molecular mass markers are shown on the left, and the inferred identities of exosome subunits are shown on the right. B, TRAMP (0.4 pmol) and/or core exosome (0.4 pmol) incubated in a 10-μl reactions in the presence of 3 fmol of 5′ [³²P]RNA substrate, ATP (500 μm), and the indicated concentrations of Mg²⁺ (Mg₂OAc) for 60 min at 30 °C and analyzed as Fig. 1. The values listed below the lane numbers represent the average ± S.E. for the amount of substrate remaining after incubation and are calculated from the results of two independent experiments.